Mechanical ingot stripper



June 12, 1962 sHlNTARo NAKAMURA 3,038,222

MECHANICAL INGoT STRIPPER 2 Sheets-Sheet 1 Filed April 19, 1960 June 12,1962 sHlNTARo NAKAMURA 3,038,222

MECHANICAL INGQT STRIPPER Filed April 19, 1960 2 Sheecs--Sheei'I 23,033,222 Patented .lune 12, 1962 3,038,222 MECHANHCAL WGT STPERShintaro Nakamura, Tokyo, .l'apan (26 of No. 403 Kanegasaku,Matsudo-shi, Chiba-lien, tapan) Filed Apr. 19, i960, Ser. No. 23,]l94Claims priority, application Japan Nov. 13, i959 9 Claims. (Cl. 22-95)This invention relates to stripping mechanisms and particularly to amechanical ingot stripper 1for separating molds, hot boxes or the likefrom ingots.

While not necessarily limited thereto, the present invention isparticularly adapted for and may be advantageously used in the steelindustry for the separation of molds from steel ingots. The formation ofingots from molten steel involves the pouring of molten metal from apouring ladle into a bot-tomless and topless mold which rests on -asupporting surface and utilizes the supporting surface for a bottom.While the sides of molds are usually tapered upwardly and inwardlyslightly to facilitate the separation of the mold from the ingot afterthe ingot has cooled, the ingot tends to stick to the mold and it isordinarily necessary to utilize considerable :torce in separating themold fromthe ingot. A variety of stripping devices have been heretoforeutilized for this purpose, including special :stripping cranes which areparticularly designed for the separation of molds from ingots. However,stripping cranes are quite complicated in nature, extremely large insize and may not be used for general purposes. Portable ingot strippers,which are hung by the hook of a common crane, hoist, or other liftingdevice, are generally more economical and flexible in use and the ingotstripper of the present invention is of this type.

Portable ingot strippers may be classified as being either purelymechanical in nature or power operated. Both types generally include apair of gripping arms or hooks for clasping the mold and pullingupwardly thereon, and a stripping ram or plunger which pressesdownwardly on the ingot simultaneously with the lifting of the mold. Inpurely mechanical ingot strippers, the lifting force of the crane,tending to raise the ingot off of the ground, is transmitted throughlevers to push downwardly on the ingot, while in power driven ingotstrippers an elecrtic motor or hydraulic fluid is used to force thestripping ram downwardly against the ingot. While hydraulically operatedor motor driven ingot strippers have possessed certain automaticfeatures, they nonetheless are of limited portability, due to theelectric wires or hoses connected to the stripper which interfere withits free transfer. Moreover, ingots are handled at relatively hightemperatures and special precautions must be taken to protect the motorsor other heat-sensitive parts from excessive heat. While purelymechanical strippers may be transferred from place to place with greaterease and are less subject to damage or mechanical failure, they haveheretofore been limited in the operations which they could automaticallyperform. Upon the application of the stripping device to a mold, it hasbeen necessary for a workman to manually apply the gripping arms orhooks to the mold and manually remove the mold from the strippingmechanism upon the completion of the operation. Such manual steps Iarenot only cumbersome, time consuming and costly, but due to the hightemperatures at which the molds and ingots are handledJ such excessivehandling of the stripper in potentially dangerous.

The inventor of the present invention, therefore, proposed some time agoa mechanical ingot stripper which is automatically operable upon thelowering and lifting of the device to grasp the mold between a pair ofgripping arms, strip the mold from the ingot, release the mold in adesired location and maintain the gripping arms and ram in a positionready to grasp and strip another mold upon being lowered into engagementtherewith.

Said ingot stripper has an outer frame composed of a pair of suspensionlinks pivoted on a hook adapted to be lifted by a lifting chain or thelike of a crane and a pair of links connected to said suspension linksat their outer ends and joined together on a pin at their inner ends, aninner frame composed of a pair of suspension links pivoted on a tubefixed to the hook and a pair of gripping arms which are connected to thesecond suspension links at -their outer ends and joined together attheir intermediate points by a pin, a lock key spindle slidably mountedin the tube xed to the hook and connected to the pin on which theintermediate points of gripping arms are joined, a locking chamberprovided below the tube and adapted to lock and release the key spindleby rotating by means of cams to hold the gripping arms open or closed byxing the distance between the locking chamber and the pin joining theintermediate points of the gripping arms, and a ram connected to the pino-n which the inner end of the links of the outer frame are pivoted andadapted to apply pressing force to an ingot in the mold when the hook israised utilizing the links as levers having fulcrums at theirintermediate points which are connected by connecting links to the pinjoining the gripping arms which pin being connected to a stand placed onthe mold. This ingot stripper has many advantages over the conventionalingot strippers but the construction is rather complicated due to thefact that the locking key spindle is always located in the lockingchamber and the tube below the hook and the stand to be placed on themold are always connected by the key spindle whether it is locked orreleased even if the distance between them is varied.

Furthermore, it is impossible to perform the stripping operation whenthe mold is a type which is tapered downwardly since a mold is alwayslifted while an ingot therein is pressed downwardly with the ram of thestripper.

The object of the present invention, therefore, is to eliminate suchdisadvantages of the lstripper of the former invention and to provide aningot stripper of simple construction which has the key spindleseparable from the locking chamber and can be used for stripping aningot from a mold irrespective of whether a mold is tapered upwardly ordownwardly or not tapered at all.

According to the present invention the powerless ingo't stripper forremoving a mold from an ingot comprises a hook adapted to be attached toa hoisting device of a crane, a pair of tongs connected to the hookthrough a system of links including a lazy tong linkage and adapted tobe closed -to grip a body located between the pair of tongs, a tongs keyautomatically operable to be locked and unlocked in a locking chamberprovided in a block carrying the tongs by the up and down motion of thehook caused by the hoisting device of a crane and adapted to keep thetongs in opened condition when it is locked, and a device adapted topress down another body to be removed from the first body when thelatter is being gripped and pulled up by the tongs, the tongs key beingseparable from and insertable into the locking chamber and the spindleof the key being rotatable by means of cams provided in the insidecircumference of la tube in which the -top portion of the spindle isinserted to effect the locking and unlocking o-f the key in the lockingchamber.

Other objects and advantages of the present invention will becomeapparent from the following detailed description taken in conjunctionwith the accompanying drawings wherein: Y

FIG. l is a general `front View of the ingo-t shipper according to oneof the embodiments of the present invention;

FIG. 2 is a side view of the same;

FIGS. 3, 4 and 5 are views on an enlarged scale itllustrating theconstruction of a key which has been known prior to the presentinvention but not in a stripper of the type of the present invention,FIG. 3 being a view illustrating a tube in which a key spindle isrotatably mounted, FIG. 4 a front view of the key spindle and FIG. 5 aside view of the same respectively;

IG. 6 is a general view of the ingot stripper according to anotherembodiment of 4the present invention; and

FIG. 7 is a side view of the same.

The rst embodiment of the present invention illustrated in FIGS. 1 and 2has arm levers 1, 1', the outer ends of which are hinged at 2, 2 to theouter ends of suspension levers 3, 3 respectively. The lower ends of thearm levers 1, 1 are pivoted together by a pin 4 while the suspensionlevers 3, 3 are connected to a hook 5 by a pin `6, the system of leversis designated as a lazy tong linkage which is adapted for being movableto extended and retracted positions. The dotted position of member 26illustrates the lazy tong linkage in the retracted position, the solidportion of 26 illustrating the lazy tong linkage for assuming theextended position, the said hook being connected to the hoisting rope ofa crane (not shown) which is transportable. The pin 4 is slidable alonga slot 7 provided in a support member 8 upstanding from a base pressingplate 9 and the lower ends of the levers 1, 1 and a cam 10 are pivotedon the pin 4.

The levers 1, 1 are yalso connected to the top part of the supportmember `8 by a pin 11 through connecting links 12, 12 the lower ends ofwhich are pivoted respectively to intermediate points 13, 13 of thelevers 1, 1'. These intermediate points are selected much closer to thepin 4 than to the outer ends 2, 2' of the levers 1, 1 and act asfulcrums for the rotation of said levers. On the pin 4 is also mounted aram rod 14 which is movable up and `down with the pin 4. Giipping armsnamely tongs, 15, 15 are hung from pins 16, 16 on the top portion of thesupport member 8. The tongs 15, 15 are closed to grip a mold 17 by theirweight but it is preferable to provide springs 18, 18 to pull theminwardly to secure the grip even if the apparatus is tilted by somechance during its operation. A tongs key 19 is xed to the upper ends ofthe levers 3, 3' and is adapted to enter into a key lock chamber 20provided on the upper end of the support member 8 and to beautomatically rotated by an angle of 90 to effect locking.

When the key is further rotated by an angle of 90, it is unlocked. Sucha locking system has long been known in the ant and it will scarcelyrequire any specic explanation. However, it will be brie-ily explainedwith reference to FIGS. 3, 4 and 5 for the sake of better understandingof the apparatus of the present invention.

The key 19 is composed of a tube 21 which has a wave shaped upper cam 22and a wave shaped lower cam. 23 to form a groove 24 extendingcircumferentially. In this circumferential groove 24 is inserted a.transversal projection 25 of a cylindrical key spindle 26 as shown inFIGS. 4 and 5, extruding the lower end 20' from the bottom of the tube21. When the hook 5 is lowered, the cylindrical key spindle 26 entersinto the key lock chamber 20 and the end of the cylindrical key spindle26 abuts against the base of the key lock chamber 20, which is integralwith the support member `8. Accordingly when the hook is furtherlowered, the projection 25 of the key spindle 26 comes into contact withthe upper cam 22 and is rotated by an angle of 45. Then when the hook 5is lifted thereby raising the tube 21 having the cams 22, 23, theprojection 25 of the cylindrical key spindle 26 comes into contact withthe lower cam 23 and is rotated by a further angle of 45 to complete therotation of 90 of the cylindrical key spindle 26. When the key spindle26 is rotated by an angle of 90, the lower end 26 of said key spindlecomes into engagement with the key lock chamber 20. It is apparent thatwhen the key 19 is `lowered again and lifted, the cylindrical keyspindle 26 is again rotated by an angle of 90 and the engagement betweenthe lower end 26 of the cylindrical key spindle 26 and the key lockchamber 20 is released and the key 19 can be lifted upwardly beingseparated from the key lock chamber 20.

The suspension levers 3, 3' have also first restraint links 27, 27 eachof which has one end pivoted at an intermediate point 2S or 28 of thelevers 3, 3 and the other ends forming brake shoes 29, 29 respectively.These links 27, 27 are connected respectively to the top portion of thesupport member `8 through second restraint links 30, 30 connected tointermediate points 31, 31 of the links 27, 27 as shown in the drawing.

The operation of this apparatus is as follows: Assume that the hook 5 islowered to place the support 3 of the apparatus on a mold 17 when thekey 19 is locked in the key lock chamber 20. The end of the key spindle26 abuts against the bottom of the key lock chamber 20 but the tube 21of the key continues to descend and hence the upper cam 22 of the tube21 cornes into contact with the projection 25 of the key spindle 26 torotate it by 45 When the hook 5 is raised from this condition, the tube21 of the key 19 is raised to bring the lower cam 23 into contact withthe projection 25 of the key spindle 26 to rotate it by further 45. Asthe result, the key 19 is unlocked and can be raised being separatedfrom the key lock chamber 20. The lifting of the hook 5 brings about therise of the outer ends 2, 2' of the levers 1, 1 and tends to lower thepin 4 at the lower ends of said levers, rotating the levers 1, 1 aroundtheir fulcrums 13, 13.

When the pin 4 is thus lowered, the gripping arms 15, 15 are closed togrip the mold 17 since there is no interfering cam 10 between the arms15, 15 any longer.

The pin 4 is connected to the ram 14 adapted to press downwardly aningct 32 in the mold 17 and the `force pressing the ingot 32 will begreatly intensitied because of the ratio of the arm lengths from thefulcrum 13 to the outer end 2 and the inner end 4 of the levers 1 and 1.The gripping arms 15, 15 clamp the mold and tend to lift the mold 17when the hook 5 continues -to be raised while the ram 14 tends to pressdown the ingot 32. Thus the stripping of the ingot 32 from the mold 17can be effected.

If the hook 5 is lowered after effecting t'ne stripping to place Ithesupport member 8 on the mold 17 and the lowering of the hook 5 iscontinued, the key 19 will enter the key lock chamber 20 on the top ofthe support member 8 and the key spindle 26 will be rotated by the uppercam 22 and then, when the hook is lifted, by the lower cam 23 of thetube 21 thereby locking the key 19 in the key lock chamber 20. When thekey 19 is lowered suiiiciently to be locked in the key lock chamber 20,it is evident that levers 1, 1 are opened to bring the cam 10 in araised position in the slot 7 to open the tongs 15, 15.

Under this condition where the tongs 15, 15' are locked in openedcondition, the crane carrying this apparatus can be transported to anydesired place to descend this stripper on a new mold to carry outanother stripping operation as described above.

Should the hook 5 be raised when the key 19 is unlocked with no control,the pin 4 may come down to the bottom end of the slot 7 and may receivesuch a great stress that it may be broken. The links 27, 27 act toprevent such an incident by stopping the lowering of the pin 4 by thebrake shoes 29, 29 which are adapted to engage with the sides of thelinks 30, 30 before the pin 4 reaches the bottom end of the slot 7.

However, the stripper of FIGS. 1 and 2 cannot be used for stripping aningot from a mold when Ithe mold is tapered downwardly or has a largercross section at the top. In order to eliminate this disadvantage, the2nd embodiment as illustrated in FIGS. 6 and 7 is contrived.

In this embodiment, a hook 105 is connected with the top end of a lazytong linkage constituted by a pair of suspension levers 103, 103'including pin 106, the other ends of said levers are pivotally connectedby pins 102, 102' with outer ends of a pair of arm levers 101, 101'. Theother ends of the levers `101, 101 are connected at points 116, 116' tothe opposite sides of a support member 108 integral with a base plate109 which is adapted to be placed on a mold 117 tapered downwardly.Levers 112, 112 constitute the closing members of the lazy tong linkage.A pair of gripping arms or tongs 115, 115 of L-shape are crossed andpivoted by a pin 104 at the crossing point.

The upper ends of the tongs are connected to the lower ends of a pair oflinks 127, 127 the top ends of which are pivoted together by a pin 128.Links 127, 127' and gripping tongs 115 and 115 constitute a scissorlinkage for engaging the ingot. The support member 108 has an upper slot137 and a lower slot 107 and the pin 128 joining top ends of the links127, 127 is slidably inserted in the upper slot 137 while the pin 104joining the tongs 115, 115' at their intersecting point is slidablyinserted in the lower slot 107. 'Ihe top ends of a pair of connectingrods 112, 112 are piyoted on the pin 128 and the lower ends of said rodsare pivotally connected to the levers 101, 101' at their intermediatepoints 113, 113 as shown in FIG. 6. A tongs key 119 having theconstruction -similar to the tongs key 19 of FIGS. 3-5 is iixed to thetop ends of the links 127, 127 and a key lock chamber 120 is providedbelow the tongs key 119 in the support member 108. When the key 119 islowered, it enters the key lock chamber, and is locked or unlocked bythe rotation of the key spindle v126 as already explained with referenceto FIGS. 3-5.

From the construction as described above, it will be evident that whenthe key 119 is locked in the key look chamber 120, the distance betweenthe two pins 104 and 128 is limi-ted and the tongs 115, 115 aremaintained in open condition.

The operation of the stripper is las follows:

Now assume that the key 119 is locked in the lock chamber 120 and thetongs 115, 115 are open. When this stripper is lowered onto a mold 117lfrom which the feeder head 132 of an ingot 132 is projected, passingthrough a hole provided in base plate 109 of the support member 132, thefeeder head 132 will come between the tongs 1,15, 115. After placing thebase plate 109 on the mold 117, the hook 105 is lifted. When the hook'is lifted, the pin 128 is lifted through the links 103, 101, 112 and103', 101', 112. This lift of the pin :128 causes the rotation of thekey spindle 126 of the key 119 to unlock said key and hence, the liftingof the pin 128 may be continued until the tongs 115, 115 clamp thefeeder head 132 of the ingot. After the grip of the feeder head 132',the hook 105 continues to be lifted, and the pins 102, 102' of the leverarms 101, 101 are lifted. Accordingly said levers tend to rotate aroundthe pins 113, 113 as the fulcrums.

The length between the pin 113 and the inner end 116 of the lever ismuch smaller than the length between the pin 113 and the outer end 102of the lever, and hence the pressing force applied to the mold 117through the support member 108 and the pressure plate 109 will begreatly intensified. The ingot 132 is pulled up by the tongs 115, 115while the mold 117 is pressed down by the inner ends 116, 116 of thelevers 101, 101', and consequently the stripping of an ingot from a moldtapered downwardly can be eifected.

When the stripper having the key 1 19 unlocked is lowered again on amold, the key 1.19 `will enter in the key lock chamber 120 and the keyspindle 126 is rotated to loc-k the key in the key lock chamber 120, andwhen the hook 105 is lifted, the tongs 115, 1115 are kept in opencondition and the stripper may be transported by a crane to a new moldto carry out the stripping operation in respect of said mold.

As explained above, the stripper of the present invention has a tongskey which can be separated entirely from an associated key lock chamberand the construction can be made much simpler than the stripper of theformer invention in which the tongs key must alrways be located in a keylock chamber. Furthermore,

the stripper of the present invention can be used for the stripping ofan ingot from a mold irrespective of whether the mold is taperedupwardly or downwardly or is not tapered at all different from thestripper of the former which cannot be used when the mold is tapereddownwardly.

What I claim is:

l. Apparatus for separating mold and ingot members comprising aplurality of links pivotally connected together to form a lazy tonglinkage, said linkage being movable between extended Iand retractedpositions, means for engaging said mem-bers to exert forces thereon toseparate the same, the latter said means being coupled to the lazy tonglinkage for separating said members as the lazy tong linkage isextended, and means for locking the lazy tong linkage to said lattermeans with the lazy tong linkage in retracted position to enablepositioning of said latter means relative to said members so that saidlatter means can separate said members as said lazy tong linkage isextended, said means for locking the lazy tong linkage to said lattermeans including a tongs key coupled to said lazy tong linkage andmovable therewith, said key including a pair of axially aligned camsurfaces in spaced relation and a key spindle in part between said camsurfaces and adapted to move axially therebetween; said means forengaging said members defining a chamber which is aligned with said keyspindle, said key spindle being lockable in said chamber to lock thelazy tong linkage to said latter means, said key spindle bein-g lockedand unlocked in said chamber in accordance with respective movement ofsaid cam surfaces relative to said key spindle, said movement of saidcam surfaces being controlled solely by extending and retracting saidlazy tong linkage.

2. Apparatus as claimed in claim l wherein said means for engaging saidmembers includes a support adapted for being positioned on one of saidmembers yand a pair of tongs pivotally supported on said support forengaging said one member in gripping relation, said chamber forIaccommodating said key spindle being provided in said support.

3. Apparatus as claimed in claim l wherein said means for engaging saidmembers includes a support adapted for being positioned on one of saidmembers, a pin operatively coupled to the lazy tong linkage andsupported for mo'vement in said support in accordance with extension andretraction of said lazy tong linkage, a scissors linkage connected tosaid pin for opening and closing in accordance with movements inopposite direction of said pin, said scissors linkage including grippingmeans for engaging the other of said members.

4. Apparatus as claimed in claim 2 wherein said support is provided witha slot, a pin pivotally connecting a pair of the links of said lazy tonglinkage and slidably supported in the slot in the support, a pair oflevers pivotally connected together at said support, each lever beingpivotally connected to one of said pair of links of the lazy tonglinkage whereby said pin moves in said support in -accordance withextension and retraction of said lazy tong linkage.

5. Apparatus as claimed in claim 3 ycomprising a further pin connectingsaid scissors linkage, the latter being slid-ably supported in saidsupport in aligned relation with the iirst said pin, said tongs keybeing supported for movement with the first said pin, said chamber beingassociated with the further pin for movement Itherewith.

6. Apparatus as claimed lin claim 4 comprising a cam on said pin andpositioned between said pair of tongs for 7 engaging the same with thepin in a position corresponding to the retracted position of said lazytong linkage such that said tongs are spaced from said one member.

7. Apparatus as claimed in claim 4 comprising a ram rod on said pin `andmovable therewith, said ram rod engaging the other of said members withsaid pair of tongs gripping said one member whereby said members areseparated as said lazy tong linkage is extended, said one memberremaining gripped by said tongs.

8. Apparatus as claimed in claim 4 comprising brake means coupled tosaid lazy tong linkage and said support for locking said linkage in theextended position with said pin in an intermediate position in the slotin the support.

9. Apparatus as claimed in claim 8 wherein said brake means comprises apair of rst restraint links, each having one end pivotally connected toone of the links of the lazy tong linkage, a brake shoe on eachrestraint link at an end remote from the first said ends, said brakeshoes being adapted to engage said lazy tong linkage to limit extensionthereof, and a pair of second restraint links, each having one endpivotally connected to a corresponding first restraint link intermediatethe ends thereof, each second restraint link having an end remote fromthe tirst said end thereof and pivotally connected to said support.

References Cited in the lile of this patent UNITED STATES PATENTS472,436 Cornelius Apr. 5, 1892 2,063,656 Bigler et al. Dec. 8, 19362,148,625 Joliet Feb. 28, 1939 FOREIGN PATENTS 740,544 Germany Oct. 22,1943 908,665 Germany Apr. 8, 1954

